The invention concerns a rearview mirror, in particular, an outside rearview mirror for motor vehicles having a pivot connection with a safety catch.
It is common knowledge to place a pivoting connection between a mirror housing which contains a mirror pane and a support structure which supports the mirror housing on a part of a body of a vehicle, wherein, this pivoting connection possesses at least one safety catch allowing the mirror housing to releasably fix itself in an operational position. Should sufficient force be brought against the mirror housing, then the safety catch of the support structure would be overcome or disengaged. When this happens, the mirror housing is movable out of its operational position, in which it is essentially held outwardly and away from the vehicle body, and into a folded position, in which the mirror housing becomes approximately parallel to the vehicle body. In this position the mirror housing gains a lesser outward exposure than when it was swung away from the vehicle body.
The safety catch of the mirror housing in relation to the support structure can be accomplished by a spring loaded sphere, which is seated in an appropriate recess. During normal operation, that is, with the mirror housing snapped into its operating position, the safety catch must be sufficiently resistant, to withstand the impacts and forces which are common in normal operation. Such forces include, for instance, wind forces, which can be very substantial in the case of larger mirror housings and high speed driving. Further, the safety catch between the mirror housing and the support structure must be vibration free, in order to be able to assure a non-impeded view from the rearview mirror.
Demands of the service call for a safety catch device or detent system with relatively high holding power. This is because the mirror housing is not to be moved out of its operative position into the folded position for trivial reasons, and for such movement, a substantial force is needed.
The relatively high forces are not critical, when they are brought against the mirror, when, for instance, with very slow moving speeds (truck positioning, parking, etc.) should the mirror housing strike a rigid obstruction with substantial force, then the mirror housing is slowly moved out of its safety catch. Damages to the mirror housing and/or the mirror pane and/or the safety catch apparatus are excluded by the described means.
The situation is reversed, however, when sudden striking or impact forces act upon the mirror housing. In this case, the forces need not be so great, that they move the mirror housing out of its safety catch position, but, because of the application of forces, the mirror housing and especially the therein inset mirror pane can suffer damages.
Contrary to these experiences, the present invention has the purpose of so creating a pivotable rearview mirror with a safety catch, that damages to the mirror housing and/or mirror pane and/or the support structure can be assuredly avoided.
To achieve this purpose, the present invention proposes, that the safety catch between the mirror housing and the support structure be releasable upon the approach of the mirror housing to an obstruction.
Regardless as to how fast the vehicle is moving or how strong the striking or impact forces are, in the case of a collision of the mirror housing with an obstruction, the mirror housing can be moved out of its detent operational position with almost no force being exerted, since, at the critical time, i.e. upon the approach of the mirror housing to the obstruction, the safety catch between mirror housing and the support structure releases.
For the moving of the mirror housing from its operational position, into the folded situation, it is no longer requisite, that the detent force of the safety catch be overcome, so that the mirror housing is moved in a resistance free manner into its folded up position.
Other advantageous developments of the invention also are provided.
Advantageously, a sensor is present, which recognizes the approach of the mirror housing to the obstruction. By the use of a sensor, the object of the present invention can be realized in a multitude of forms, as will be shown in the following description.
Furthermore, the sensor is preferably placed in the mirror housing and reacts within a fan shaped space before and to the side of the vehicle. Through the placement of the sensor(s) in the mirror housing, a direct connection is given between a possibly detected obstruction and the mirror housing, so that complex computations are dispensed with, which, for instance would have been necessary if the sensor was located in the forward bumper, etc. There can be more than one sensor placed in the mirror housing to bring about a panoramic detection area, so that even obstructions advancing on the mirror housing from the rear (for instance, upon backing up) can be picked up.
A multiplicity of kinds of sensors are possible. For instance, among these are ultrasonic, infrared, or radar. In each case, the sensor should possess the ability of functioning in darkness, in poor visibility conditions (rain, fog etc,.) or under other unfavorable conditions and be able to detect the approach of an obstruction.
The sensitivity and/or the distance of reactivity of the sensor can be adjustable, in accord with a further preferred embodiment.
The safety catch between the mirror housing and the support structure can, again, be provided in a plurality of embodiments. For instance, the safety catch can be held by electro-magnetic means, whereby, upon the approach of an object, the magnet can be shut off by a circuit breaker, so that the mirror housing is then essentially force free swingable against the vehicle body.
In accord with another embodiment, the safety catch can be actuated by a permanent magnet which, upon the approach of said object, is masked by the application of an opposite magnetic field, preferably engendered electro-magnetically, thus releasing the said safety catch as above.
Finally, the safety catch can be held with simple mechanical means, and, upon approach by an obstruction accordingly unlocked, a procedure which again is preferably done by electro-magnetic means.
It is desirable to avoid possible collisions of the mirror housing with the obstructing object, which could be damaging to the mirror housing and/or the mirror pane and/or the support structure. Such damage could occur even though the safety catch is released and, the mirror housing could move essentially force-free in relation to the support structure.
In accord with another embodiment, following the release of the safety catch, the mirror housing can be moved into its folded position by spring power. For this action, the presence of a tensioned spring or a torsion spring in the area of the pivot axis between the mirror housing and the support structure is necessary. A spring of this kind, when the mirror housing is in its outwardly extended position, i.e. in its operational position, sets the said mirror housing under tension in this operating position and upon the release of the safety catch, the spring works in such a manner, that the mirror housing pivots into its folded position.
Instead of the spring power, the mirror housing can also be moved by means of a motor into its folded position. The advantage in this case is that after the obstruction has been passed by, the mirror housing, by means of the same motor, which then runs in reverse, can be moved back into its operating position, that is, its outwardly extended position.
The releasing of the safety catch between the mirror housing and the support structure can further be made with current cut-off. This is advantageous, if the vehicle must be maneuvered in close quarters to building wall or the like.
In this case the close proximity to what would normally be obstructions would cause the sensor(s) to react, so that the mirror would be moved out of the extended operational position into the folded position, in case the spring loading or the motor drive between the mirror housing and the support structure came into use. Since by close loading/unloading maneuvering, especially when backing, the driver of a vehicle relies upon the outside rearview mirror. Accordingly, exactly then, if an automatic folding retraction occurs of the mirror, the situation is very unwelcome. On these grounds, the driver can preferentially cut out this automatic-retraction into the fold-up position, when he knowingly must approach or drive by close to what would otherwise be obstructing objects.